‘Fighting a losing battle with the sea’

Scientists increasingly believe the rise in sea levels will accelerate markedly as ocean waters warm and ice sheets melt. The effect could be greatest in the Northeast, where many sea walls are in woeful disrepair.

Scituate’s sea wall has been hit hard by storms that pose an increasing threat, like one that recently sent waves crashing in.
(Jonathan Wiggs/Globe Staff)

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One in an occasional series of articles on sea level rise in New England.

SCITUATE — A piercing wail startled Gary and Paula Elsmore awake at 3 a.m. Paula knelt on the bed and peered out the upstairs bedroom window. In the blinding snow, she could barely make out a neighbor waving up at her frantically.

The ocean was coming.

Fierce seas had overtopped a sea wall about three blocks away, and the roiling water was now heading straight toward the Elsmores’ neighborhood.

“You could see the storm surge, it was bending all the backyard fences one way as it came in,’’ Paula Elsmore said of that late December night.

The Elsmores’ basement filled with 5 feet of water, and flames billowed into the dark sky from two nearby houses that flooded and caught fire. Their neighbors’ young children had to be evacuated from their house by a bucket loader. In all, some 400 homes were swamped.

The ocean’s fury is an omnipresent threat for the growing number of people who live at its edge. But accumulating scientific evidence suggests that our warming climate could cause sea levels to rise faster than previously thought, making storm surges like the one that pummeled Scituate more dangerous.

Several lines of research now indicate thata 3-foot global rise by 2100 is a plausible scenario, though some scientists forecast a smaller rise. In other words, what was once a problem for our great great-grandchildren is one our children could confront.

And it is possible the news could be even worse in the Northeast. Studies showthat changes in ocean circulationdriven by warming waters could raise sea levels an additional foot or more along New England shores by the end of the century.

Already, 65 acres of prime Massachusetts coastal real estate is swallowed by the sea every year; ocean waters have crept up about a foot here in the last century. While more land will be eaten away, storm surges — abnormal rises of water during severe weather — layered on top of higher seas could push much further inland, especially in flat coastal areas of New England, and oceanside homes in places like Scituate and Gloucester will be even more vulnerable. Some scientists say that climate change may also bring fiercer and more frequent storms.

As the Scituate flood demonstrated, the region is woefully ill-equipped to hold back a rising ocean. In some places along the Bay State’s coast, concrete and boulder barriers, most more than a half-century old, protect billions of dollars worth of property. In the last five years, several sea walls have partially or entirely failed in Massachusetts, including ones in Gloucester, Marshfield, and Oak Bluffs.

Deeply concerned over the projected sea level rise, state officials commissioned a massive inventory of publicly owned sea walls and other coastal barriers four years ago. Almost 165 structures, whose failure would result in significant property damage, were declared in fair, poor, or critical condition, but only a fraction of them have been fixed because of the budget crisis. The price tag to repair and fortify all of them against rising seas is huge: more than a billion dollars.

“We are now facing a societal debate about how much people want to pay — and who pays — for coastal defense,’’ said S. Jeffress Williams, a coastal marine geologist and scientist emeritus with the US Geological Survey Woods Hole Science Center.

Rick Murray, a professor of earth science at Boston University and a Scituate selectman, puts it more bluntly: “Not everything we love can be saved.’’

A bull’s-eye for Boston In 2007, a scallop fisherman on Georges Bank some 90 miles off Massachusetts hauled up an intriguing artifact of sea level rise: A 2-foot-long mastodon tusk.

The elephantlike animal roamed Georges Bank when it was exposed land during the last ice age. But as ice sheets and glaciers melted and sea levels rose, the water entombed the remains of the banks’ land-based life. That rise slowly and naturally continues today.

New England also slowly sinks a small amount every year as it settles from that era. Just as pressing a balloon in one spot will cause it to bulge in another, the ice sheet’s weight caused land under it to sink and land along the glacier’s margins to rise. Now, the land is slowly settling back.

The end result of that gradual sea level rise and sinking land is that the Atlantic has long been rising along our coast about a tenth of an inch each year.

Now, that pace is expected to accelerate. Oceans are heating up as the atmosphere warms from the release of heat-trapping gases from power plants, factories, and cars. Warmer water takes up more space, raising sea levels. And, as if a water faucet has been turned on, melting glaciers and ice sheets in Greenland and Antarctica are filling the oceans with trillions of gallons a year more water.

Four years ago, the Intergovernmental Panel on Climate Change, a scientific body that advises the United Nations, estimated the world’s seas could rise almost 2 feet by 2100. But now, many scientists say 3 feet is plausible, especially as evidence builds that ice sheets are melting faster. Earlier this month, a research team led by University of California, Irvine scientists, using two independent techniques, showed that to be the case in Greenland and Antarctica.

Seas may riseeven higher in the Northeast.

In recent years, scientists have used powerful computers to run simulations of how sea level may vary in different regions. While they caution the work is preliminary and fraught with uncertainty, they say a common feature of these simulations is that the East Coast of the United States, and especially the Northeast, experiences a higher sea level rise than the global average.

The reason has to do with a giant Atlantic Ocean circulation system that funnels warm water north on the Gulf Stream, only to have it cool at high latitudes and sink deep in the ocean, where it slowly makes its way south again.

In 2009, Jianjun Yin, a climate modeler at the University of Arizona, published a paper in the journal Nature Geoscience that showed the circulation system could slow as the North Atlantic warms, possibly allowing water to pile up along the Northeast coast about 8 inches morethan the global average. Later that year, a team led by Aixue Hu, from the Boulder-based National Center for Atmospheric Research, showed moderate or high melting of the Greenland ice sheet could add another 4 inches and maybe more to that total because the fresh, warming water would further slow the circulation system.

It is hardly the Armageddon portrayed in the 2004 movie “The Day After Tomorrow,’’ which chronicled a catastrophic change in ocean systems, but the extra 12 inches or more could pose an extraordinary risk for a society that has crowded itself close to the sea.

“Centers of economy, politics, culture, and education are located along that coast,’’ said Yin.

Regional seas are also strongly influenced by a longoverlooked force: The gravitational pull of enormous ice sheets.

Work by Jerry Mitrovica, a Harvard geophysicist, and others shows thatthe Greenland and West Antarctic ice sheets and other glaciers are so large they have their owngravitational pull, drawing sea water close around them. As ice melts, that pull weakens and sea levels fall locally butincreasingly rise as waters flow toward the opposite pole. Melting of these icesheets is projected to dramatically alter regional sea levels, butthere is uncertainty on timing and how those effects will interactwith other sea level influences.

“It’s not our experience to think about what happens on the otherside of the world affecting us,’’ said James Davis, a research professor who studies the effect of gravitation on sea level at Columbia University’s Lamont-Doherty Earth Observatory. “But it does.’’

There are about 140 miles of publicly owned sea walls or other structures along the Massachusetts coast that are designed to protect billions of dollars worth of property. Most were designed to last a half-century, but the vast majority are older.

The state’s study rated each structure on its condition and priority to be fixed, depending on how much damage it would cause if it failed. While the majority were given good grades, some sea walls that failed in recent years, such as in Scituate and Gloucester, were given adequate ratings, meaning that in just four years they became structurally unstable, surveyors missed weaknesses, or the storm’s fury was especially focused.

State officials said the ratings did not take into account rising sea levels. They do not know how well the walls will hold as seas rise.

“We know that sea level rates are going to accelerate,’’ said Bruce Carlisle, acting director of the Massachusetts Coastal Zone Management agency. “This is not a problem we are going to solve overnight.’’

Money is a perennial problem. Officially, the price tag to fix all the seawalls is more than $600 million, but state Department of Conservation and Recreation officials say that will be enough only to repair the walls, not to redesign, strengthen, or raise some to protect against sea level rise. For that, more than $1 billion is needed. The state allocates about $1.2 million a year for communities to plan and design sea wall repairs. State officials acknowledge the sum is woefully inadequate, but it is unlikely to increase, given the budget crisis. On Tuesday, a State House hearing will examine ways to increase funding.

Sea walls have gotten so precarious in communities such as Hull that residents have taken it upon themselves to fix the publicly owned barriers.

“It was that or lose our homes,’’ said Gary Bloch, a resident of the Point Allerton neighborhood of Hull who, along with several other residents, paid $60,000 each to raise the state-owned sea wall and strengthen it about 12 years ago. It is already in critically bad shape again, according to state officials, but state money to fix it is lacking.

Sea walls helped shape Massachusetts. As people discovered the joys of hot summer sand and cool ocean breezes, they flocked to build homes in coastal communities. Sea walls went up in the 1930s, ’40s, and ’50s to protect their investments.

It did not take long for property owners down the coastline from sea walls to notice something missing: sand. While the hard structures protect homes behind them, they often lead to erosion of unprotected adjacent properties by interrupting the supply of sand that waves normally move along the shore. In 1978, Massachusetts passed a law that largely prohibited the construction of sea walls or anything like them to protect homes built after that year.

Now, as seas advance, passions are running high on what to do. Many state and local environmental officials acknowledge that letting shorelines loose is the best answer, but they quickly add it is an impractical solution given all the homes, businesses, and roads protected by sea walls. Otherssay the best protection against rising seas is more coastal defenses, but ones better crafted to work with nature.

“The key here is to have a restored beach for natural storm protection along with hard solutions such as sea walls,’’ says Bob Hamilton of the Woods Hole Group, a private consulting firm that works with coastal homeowners and governments. Yet, he acknowledges this solution is expensive.

The arguments get most heated over who should be protected against the sea — and who should pay for it. In Scituate, for example, a group of private homeowners wants the town to rebuild a failing sea wall originally builton their properties with state funds, but officials have refused, saying it is the homeowners’ responsibility.

Some officials in oceanfront communities are advocating a far more radical and unpopular proposition: Move.

“The only real answer is retreat,’’ said Murray, the Scituate selectman. “I feel for these people. [Perhaps] they inherited their house from their great grandmother or spent a lot of money to buy it. But . . . we are fighting a losing battle with the sea.’’

Ask most anyone in Scituate about retreat and they laugh. For many, seaside living is a religion and an adventure, and they consider sea level rise a distant threat, too far off to plan for now.

The Elsmores say the same. This is the home they have owned for 30 years, where they raised three children and put on a cozy kitchen extension. Yes, the furnace, water heater, and Gary’s tools were destroyed when their sump pumps failed in the late December storm, but it had never happened before. Last month, as the couple pointed to where the water came into their house, they said they doubted it would happen again anytime soon.

“I’m not going to be around’’ for higher seas, said Paula Elsmore. “We are not going anywhere.’’

Matt Carroll of the Globe staff contributed to this report. Beth Daley can be reached at bdaley@globe.com.